MP Board Class 12th Biology Important Questions Chapter 10 Microbes in Human Welfare
Microbes in Human Welfare Important Questions
Microbes in Human Welfare Objective Type Questions
Choose the correct answer:
Name the place from which viruses entered into the plant:
(a) From lenticels
(b) From wound
(c) From stomata
(d) From root.
(b) From wound
Fertilizer elements are :
(d) All of these.
(d) All of these.
Fertilizer that supplies least % of nitrogen is :
(d) Organic nitrogen fertilizer.
(d) Organic nitrogen fertilizer.
Nitrifying bacteria converts :
(a) N2 into nitrates
(b) Ammonia into nitrates
(c) Nitrates into N2
(d) CO2 into carbohydrates.
(b) Ammonia into nitrates
Who discovered the virus :
Name the virus which has double helical stranded DNA :
(a) Hepatits A
(b) Hepatits B
(c) Hepatits C
(d) Flepatits D.
(b) Hepatits B
Spirally coiled bacteria is known as :
Name the bacteria in which flagella are found in whole body :
Useful activities of microbes is :
(a) Nitrogen fixation
(c) Biogeochemical cycle
(d) All of the above.
(d) All of the above.
Which of the following is prokaryotes :
Yeast is used in the production of :
(a) Ethyl alcohol
(b) Acetic acid
(a) Ethyl alcohol
B.T. cotton provides immunity from :
Which is the used for making bread :
(d) S. cerevisiace.
Fill in the blanks:
- Rhizobium, Azolla and Anabaena are the example of …………………….. fertilizers.
- …………………….. bacterium is found in the roots of leguminous plants.
- Nostoc and Anabaena are called ……………………..
- …………………….. is nitrogen fixing bacteria.
- …………………….. is the fungal resistant, bacterial antibody component.
- …………………….. is the other name of mycoplasma.
- …………………….. is the other name of Archaebacteria.
- …………………….. type of ribosome is found in Moneran.
- Bacterial cell wall is made by ……………………..
- …………………….. is the meaning of word virus.
- Butter milk is obtained from the activation of ……………………..
- Ethanol is produced in a large scale through …………………….. yeast.
- …………………….. bacteria is helpful in vinegar production.
- Living fossils
- 70S type
- Streptococcus lactis
- Saccharomyces cerevisiae
- Azotobacter aceti.
Match the followings :
Write answer in one word/ sentences:
- Name the bacteria which is used in making swiss cheese.
- Write the name of the microorganism which converted milk into curd.
- Name the fish which control mosquito.
- Write the name of two bacteria which are found in soil in free state.
- Write the full name of IPM.
- What is yogurt?
- What is interferon?
- Write the full name of B.O.D.
- Write the name of an autotrophic nitrogen fixing microorganism.
- Which microbes are used in industries for making citric acid?
- Who discovered the penicillin?
- Write the name of an alcoholic drink which is made by without distillation.
- Microbes which is respire without oxgyen is called?
- Synibiotic relationship which is found between fungi and higher plant root.
- Propionibacterium shermanii
- Azotoba – cterium and Clostridium
- Integrated Pest Management
- Milk product
- Antiviral protein
- Biochemical Oxygen Demand
- Aspergillus niger
- Alexander Fleming
Microbes in Human Welfare Very Short Answer Type Questions
Name the fungus which produce these products:
- Citric acid
- Vitamin B2
What is yoghurt?
Yoghurt is a semi – solid sourish food prepared from milk fermented by added bacteria.
Why does the river Ganga water not spoil even kept for long – time?
Bacteriophages are present in Ganga river which feed on bacteria which spoil water. So, this water does not get spoil for long – time.
Who discover penicillin?
Name the microorganism/fungi which gave penicillin.
Which organism is used for making citric acid in industries?
Write the name of methanogen bacteria.
Methano bacterium species.
Which bacteria is found in anaerobic sludge?
What is lady bird?
It is an insect which is used as biocontroller for Aphid control.
Give the name of autotrophic nitrogen fixing microbes.
Name the mineral absorbed by mycorrhiza, which is not absorbed by plant roots.
Name the microorganism which changes to milk into curd.
Which fungi is used in treatment of plant due to biological control?
Which bacteria is used in swiss paneer?
Which paneer is completed by the growth of fungus?
Name two alcoholic drink which are formed without distillation.
Beer and Wine.
Name two alcoholic drink which are formed by distillation.
Whiskey and Rum.
What is the full form of BOD?
Biochemical or Biological Oxygen Demand.
Microbes in Human Welfare Short Answer Type Questions
Bacteria cannot be seen with the naked eyes, but these can be seen with the help of a microscope. If you have to carry a sample from your home to your biology laboratory to demonstrate the presence of microbes under a microscope, which sample would you carry and why?
Curd can be used as a sample for the study of microbes. Curd contains numerous Lactic Acid Bacteria (LAB) or Lactobacillus. These bacteria produce acids that coagulate and digest milk proteins. A small drop of curd contains million of bacteria, which can be easily observed under a microscope.
Give example to prove that microbes release gases during metabolism.
The examples of bacteria that release gases during metabolism are :
- Bacteria and fungi carry out the process of fermentation and during this process, they release carbon dioxide.
- The dough used for making idli and dosa gives a puffed appearance. This is because of the action of bacteria which releases carbon dioxide. This CO2 released from the dough gets trapped in the dough, thereby giving it a puffed appearance.
In which food would you find lactic acid bacteria? Mention some of their useful applications.
Lactic acid bacteria can be found in curd. It is this bacterium that promotes the formation of milk into curd. The bacterium multiplies and increases its number, which converts the milk into curd. They also increase the content of vitamin B12
in curd. Lactic acid bacteria are also found in our stomach where it keeps a check on the disease causing microorganisms.
Name some traditional Indian foods made of wheat, rice and Bengal gram (or their products) which involve use of microbes.
- Wheat product: Bread, Cake etc.
- Rice product: Idli, Dosa.
- Bengal gram product: Dhokla, Khandvi.
In which way have microbes played a major role in controlling diseases caused by harmful bacteria?
Several microorganisms are used for preparing medicines. Antibiotics are medicines produced by certain microorganisms to kill other disease causing microorganisms. These medicines are commonly obtained from bacteria and fungi. They either kill or stop the growth of disease causing microorganisms. (MPBoardSolutions.com) Streptomycin, tetracycline and penicillin are common antibiotics. Penicillium notatum produces chemical penicillin, which checks the growth of staphylococci bacteria in the body. Antibiotics are designed to destroy bacteria by weakening their cell walls.
Name any two species of fungus, which are used in the production of the antibiotics.
Antibiotics are medicines that are produced by certain microorganisms to kill other disease causing microorgainsms. These medicines are commonly obtained from bacteria and fungi. The species of fungus used in the production of antibiotics are:
- Penicillium notatum
- Cephalosporium acremonium
What is sewage? In which way can sewage be harmful to us?
Sewage is the municipal waste – water collected from city or town homes, that contains toilet, bathroom and kitchen waste.
It contains large amounts of organic matter and many pathogenic microbes which are harmful to humans as they can cause many diseases like cholera, typhoid, polio.
What is the key difference between primary and secondary sewage treatment?
Differences between Primary and Secondary sewage treatment:
Primary sewage treatment:
- It is a physical process.
- Primary treatment involves the removal of large sized floating and suspended solids.
- BOD is not affected in this treatment.
Secondary sewage treatment:
- It is a biological process.
- Secondary treatment involves decomposition of organic matter by microbial action which produce methane, hydrogen sulphide and carbon dioxide.
- BOD is less by secondary treatment.
Do you think microbes can also be used as source of energy? If yes, how?
Yes, microbes can be used as a source of energy. Bacteria such as; Methane bacterium is used for the generation of gobar gas or biogas. The generation of biogas is an anaerobic process in a biogas plant, which consists of a concrete tank (10 – 15 feet deep) with sufficient outlets and inlets. The dung is mixed with water to form the slurry and thrown into the tank. The digester of the tank is filled with numerous anaerobic methane producing bacteria, which produce biogas from the slurry. Biogas can be removed through the pipe which is then used as a source of energy, while the spent slurry is removed from the outlet and is used as a fertilizer.
Microbes can be used to decrease the use of chemical fertilizers and pesticides. Explain how this can be accomplished.
Microbes play an important role in organic farming which is done without the use of chemical fertilizers and pesticides. Biofertilizers are living organisms which help in increasing the fertility of soil. It involves the selection of beneficial microorganisms that help in improving plant growth through the supply of plant nutrients. Biofertilizers are introduced in seeds, roots or soil to mobilize the availability of nutrients. Thus, they are extremely beneficial in enriching the soil with organic nutrients.
Many species of bacteria and cyanobacteria have the ability to fix free atmospheric nitrogen, Rhizobium is a symbiotic bacteria found in the root nodules of leguminous plants. (MPBoardSolutions.com) Azospirilhum and Azotobacter are free living nitrogen – fixing bacteria, whereas Anabena, Nostoc and Oscillitoria are examples of nitrogen – fixing cyanobacteria. Biofertilizers are cost effective and eco – freindly. Microbes can also act as biopesticides to control insect pest in plants. An example of biopesticides is Bacillus thuringiensis, which produces a toxin that kills the insect pests.
Dried bacterial spores are mixed in water and sprayed in agricultural fields. When larvae of insects feed on crops, these bacterial spores enter the gut of the larvae and release toxins, thereby it. Similarly, Trichoderma are free living fungi. They live in the roots of higher plants and protect them from various pathogens. Baculoviruses is another bio – pesticides that is used as a biological control agent against insects and other arthropods.
Three water samples namely river water, untreated sewage water and secondary effluent discharged from a sewage treatment plant were subjected to BOD test. The samples were labelled A, B and C; but the laboratory attendant did not note which was which. The BOD values of the three samples A, B, and C were recorded as 20mg/L, 8 mg/L and 400mg/L, respectively. Which sample of the water is most polluted ? Can you assign the correct label to each assuming the river water is relatively clean?
The BOD values of the three samples A, B and C were recorded as 20 mg/L, 8 mg/L and 400 mg/L. Greater the BOD of waste water more is its polluting potential. So, sample C is more polluting as compared to sample A. Hence, sample A is the secondary effluent, sample B is river water and sample C is untreated sewage water.
What is paneer? Give its preparation method.
Paneer is a milk product, which has 20 – 30% protein first filtered and the milk in thin cloth than heat on 60°C at 30 minutes and heat on 75°C at 15 second later it cold till 30°C. Add some quantity of lactic acid bacteria Streptococcus lactis, Streptococcus cremoris and enzyme renin. By this fat and casein protein is detached from milk after 45 minutes this mixture became solid. Now, they are cut into small pieces and boild in hot water, when it starts floating, they are separated and squeezed. Then they are put in salt water for treating. Paneer is now ready.
What is the utilization of bacteria in agriculture?
Uses of Bacteria : Uses of bacteria for agriculture are as follows :
- They increase soil fertility due to decomposition of dead organisms.
- They increase soil fertility through nitrogen fixation in soil.
- Blue – green algae is used the form of fertilizers.
- They balance the quantity of mineral salts.
How are the bacteria used in vinegar industry?
Fermentation of sugar by yeast in vinegar industry. Due to this manner, wine is prepared. This ethyl alcohol abandoned in direct air for much time now, it is changed in vinegar.
Name live fungi which give antibiotics.
The fungi which give antibiotics are as follows:
Name five bacteria which produce antibiotics.
The bacteria which produce antibiotics are as follows:
Microbes in Human Welfare Long Answer Type Questions
Write seven useful activities of Bacteria.
Useful activities of bacteria :
- N2 fixation : Some bacterias play an important role in nitrogen fixation example Azo – tobacter, Clostridium, Rhizobium. These bacterias increase the fertility of soil by the fixation of atmospheric nitrogen.
- Lactic acid synthesis : Lactobacillus lacti converts the milk sugar into lactic acid.
- Acetic acid synthesis: Acetobacter aceti takes part in synthesis of acetic acid or vinegar.
- Rating of fibres: Isolation of wood fibres from the stem of plants is called rating. Clostridium butyricum is used in rating of fibres.
- Tobacco and Tea industry : Some bacteria like Micococcus candisens is used to increase the flavour of the leaves of tobacco and tea. This process is called as seasoning.
- Medicine production : Bacteria are the chief source of antibiotics, hence, they are used to extract antibiotics, example Streptomyces gresius (Streptomycine).
- As symbionts: Bacteria presents in our body, helps in the various metabolic reactions example E.coli.
Write economic importance of fungi.
Following are the economic importance of fungi:
- As food : Mushrooms like Agaricus, Lycoperdon, Romaria, Clavasia are used as food. These mushrooms contain about 50% protein. Morchella is also used as food.
- As medicine : Fungi provides various types of antibiotics as example Penicillin, Griseofulvine, Citrinine, Clavicine, Gliotoxine, etc. which are used in the treatment of disease.
- Fertility of soil: Many fungi species increase the soil fertility by decomposition of dead organic matter.
- Nitrogen fixation : Many fungus like Rhodotorula increases the soil fertility by nitrogen fixation.
- In bakery industry : Yeast cells are used in bakery to produce spongy breads.
- In wine industry : Yeast cells contain enzyme zymase which ferment sugar into alcohol.
- In chemical industry : Many fungi species are used in the production of various types of acid like citric acid.
- In cheese industry : Fungus Penicillium roqueforti is used in the preparation of camembert type of cheese from milk.
Explain the uses and types of virus.
Uses of Viruses:
- As it forms a link between non – living and living thus, it helps us to understand organic evolution.
- Cyanophage (Blue – green algae) viruses are used to destroy blue – green algae grown in different areas.
- Bacteriophages are used as biocides to destroy many harmful bacterias present in polluted area.
For example : Water of the river Ganga always remain pure and clean in bottles year after year due to presence of bacteriophage in it.
Nucleic acids of viruses : Viruses generally contain only one type of nucleic acid DNA or RNA. DNA is found in animal viruses, whereas RNA is found in plant viruses.
Human Immuno Virus (HIV):
It causes AIDS disease in human. Full form of AIDS is Acquired Immune Deficiency Syndrome. This virus destroys immune system of the body, thus, the patient of AIDS suffers from number of diseases at a time and at last he dies. This virus is found surrounded by protein and a ring of RNA is found at the centre. Whole body of virus is surrounded by a covering of glycoprotein.
Type of viruses:
On the basis of host infected, viruses are grouped into following four groups:
- Animal viruses : Viruses which infect animals are called animal viruses. These viruses contain DNA as genetic material.
- Plant viruses : Viruses which infect plants are called plant viruses. These viruses contain RNA as genetic material.
- Cyanophages : Viruses that infect blue – green algae are called cyanophages. These viruses contain RNA as genetic material.
- Bacterial viruses or Bacteriophages : Viruses that infect bacteria are called as bacteriophages. They contain DNA as genetic materials.
Find out the role of microbes in the following and discuss it with your teacher:
- Single Cell Protein (SCP)
1. Single Cell Protein (SCP):
It refers to harmless microbial cells that can be used as an alternate source of good protein. Just like mushrooms (a fungus) is eaten by many people and yeast is used by athletes as a protein source; similarly, other forms of microbial cells can also be used as food rich in protein, minerals, fats, carbohydrate and vitamins. (MPBoardSolutions.com) Microbes like Spirullina and Methylophilus methylophus are being grown on an industrial scale on materials containing starch like waste water from potato processing plants, straw, molasses, animal manure and even sewage. These single cell microbes can be used as source of proteins.
2. Role of microbes in soil:
Microbes play an important role in organic farming which is done without the use of chemical fertilizers and pesticides. Biofertilizers are living organisms which help in increasing the fertility of soil. It involves the selection of beneficial microorganisms that help in improving plant growth through the supply of plant nutrients.
Biofertilizers are introduced in seeds, roots or soil to mobilize the availability of nutrients. Thus, they are extremely beneficial in enriching the soil with organic nutrients. Many species of bacteria and cyanobacteria have the ability to fix free atmospheric nitrogen, Rhizobium is a symbiotic bacteria found in the root nodules of leguminous plants. Azospirilhum and Azotobacter are free living nitrogen-fixing bacteria, whereas Anabena, Nostoc and Oscillitoria are examples of nitrogen – fixing cyanobacteria. Biofertilizers are cost effective and eco – freindly.
Microbes can also act as biopesticides to control insect pest in plants. An example of biopesticides is Bacillus thuringiensis, which produces a toxin that kills the insect pests. Dried bacterial spores are mixed in water and sprayed in agricultural fields. When larvae of insects feed on crops, these bacterial spores enter the gut of the larvae and release toxins, thereby it. Similarly, Trichoderma are free living fungi. (MPBoardSolutions.com) They live in the roots of higher plants and protect them from various pathogens. Baculoviruses is another bio – pesticides that is used as a biological control agent against insects and other arthropods.
Arrange the following in the decreasing order (most important first) of their importance, for the welfare of human society. Give reasons for your answer. Biogas, Citric acid, Penicillin and Curd.
The order of arrangement of products according to their decreasing importance is:
Penicillin – Biogas – Citric acid – Curd.
Penicillin is the most important product for the welfare of human society. It is an antibiotic, which is used for controlling various bacteral diseases. The second most important product is biogas. It is an eco – friendly source of energy. The next important product is citric acid, which is used as a food preservative. The least important product is curd, a food item obtained by the action of lactobacillus bacteria on milk. Hence, the products in the decreasing order of their importance are as follows :
Penicillin – Biogas – Citric acid – Curd.
How do biofertilizers enrich the fertility of the soil?
Biofertilizers are living orgainsms which help in increasing the fertility of soil. It involves the selection of beneficial microorganisms that help in improving plant growth through the supply of plant nutrients. These are introduced to seeds, roots, or soil to mobilize the availability of nutrients by their biological activity. Thus, they are extremely beneficial in enriching the soil with organic nutrients. (MPBoardSolutions.com) Many species of bacteria and cyanobacteria have the ability to fix free atmopheric nitrogen. Rhizobium is a symbiotic bacteria found in the root nodules of leguminous plants. Azospirillium and Azotobacter are free living nitrogen – fixing bacteria, whereas Anabaena, Nostoc and Oscillitoria are examples of nitrogen – fixing cyanobacteria. Biofertilizers are cost effective and eco – friendly.
Describe role of microorganisms in biogas production.
The gas produced by anaerobic fermentation of waste biomass or waste bi – product is called as biogas.
Role of microorganisms in biogas production:
In biogas production under anaerobic condition, microorganism including methanogenes convert the bio – degradable organic waste into biogas and humus. The whole process is completed in three stages:
1. Solubilization : In this step methanogenic bacteria hydrolyse the complex polymers into organic acids, alcohol by hydrolytic fermentation.
2. Acidogenesis : It is a biological reaction where simple monomers are Converted into volatile fatty acids, then into acetic acid, CO2 and hydrogen.
3. Methenogenesis: Anaerobic digestion occurs in which acetate and CO2 are converted into methane.